Günter Wallraff (born October 1, 1942 in Burscheid near Cologne) is a German writer and undercover journalist.
Some of his famous reports are 'Der Aufmacher', about his time as a reporter for German daily Bild, in which he exposed the paper for fabricating a significant part of its stories; and 'Ganz Unten', about his posing as a Mediteranean guest worker, and the maltreatment he received by the hands of employers, land-lords and the German government in that role.